Entropy change

In comparison to the vapour gas-compression refrigeration, magnetic heat-pumping near room-temperature is regarded to be an alternative technology due to its high energy efficiency and environmentally friendly solid-state cooling materials. The magnetic heat pump technology utilizes the magnetic field induced temperature change, which is based on the magnetocaloric effect (MCE).

7p visergeyne 18-06-2024 3 0   Download

Part 2 book "Phase equilibria in chemical engineering" includes content: Vapor liquid equilibrium, liquid liquid equilibria, liquid solid equilibrium, other topics, chemical equilibria, evaluation of changes in enthalpy and entropy, principles of experimental methods for phase equilibria.

374p muasambanhan09 04-03-2024 4 0   Download

The influence of heterogeneity, however, cannot be studied experimentally. In this study, we employed two reversed phase columns with different retention mechanisms to show that by serially coupling the columns, the obtained thermodynamic parameters are not related to the results obtained on the respective individual columns.

7p viginny 23-12-2022 5 3   Download

On the basis of slope analysis, the compositions of the extracted species were formulated as Pr(NO3)3.2Cyanex 921 and Pr(NO3)3.Cyanex 923. The percentage of extraction of Pr(III) was found to decrease with increases in temperature. The standard enthalpy and entropy changes were negative owing to the complexation with decrease in randomness without a compensatory disruption of the hydration sphere of the metal ion. Mineral acids like hydrochloric acid (0.008 M) and sulfuric acid (0.03/0.02 M) were effective for the stripping of Pr(III) from the loaded organic phase with 0.

8p langthannam 29-12-2021 8 1   Download

A model was proposed and used to calculated the changes in enthalpy (∆Ho), entropy (∆So), and Gibbs energy (∆Go), as well as equilibrium constant (K) relating to the sintering of alumina compacts. Specific nanopore volume (V) of the compacts was assumed as a thermodynamic variable. A hypothetical equilibrium constant (Kh) and corresponding Gibbs energy (∆Goh) were calculated depending on the V value measured after each sintering.

5p langthannam 29-12-2021 10 0   Download

Lecture Physical chemistry - Chemical thermodynamics: entropy, free energy and equilibrium provide students with knowledge about chemical thermodynamics, spontaneous processes, the second law of thermodynamics, entropy changes in the system, the third law of thermodynamics and absolute entropy, standard free-energy changes,...

46p bachnhuocdong 23-12-2021 12 0   Download

Lecture Power plant engineering - Module 1: Section 3. After completing this section, you will understand knowledge about: nozzles, applications, types of nozzles; relationship between area, velocity and pressure in nozzle flow; isentropic flow of a vapor/gas through a nozzle; entropy changes with friction; operation of C-D nozzle; supersaturated flow;...

23p bachkhinhdaluu 03-12-2021 23 1   Download

Gas conditioning and processing: Volume 1. The basic principles - Part 2 present the content: basic thermodynamic concepts, calculation of system energy changes, process control and instrumentation, flow of fluids, enthaply calculations for pure substances, entropy and internal energy caculations, process control system development, cascade and feed-forward control,...

240p bachkhinhdaluu 03-12-2021 14 1   Download

Ecological niche models (ENMs) provide information to assess the effects of environmental and climatic conditions on species distribution. The purpose of this study was to predict the impact of climate change on a critically endangered species, Campanula yaltirikii H.Duman. It is a local endemic chasmophyte from Mt Çığlıkara (Antalya, Turkey), restricted to cracks in calcareous rocks and threatened by goat overgrazing. Current and future ENMs of C. yaltirikii were predicted with a maximum entropy (Maxent) algorithm.

10p tudichquannguyet 29-11-2021 12 1   Download

Lecture General Chemistry 2 - Chapter 20: Thermodynamics: Entropy, Free Energy, and the Direction of Chemical Reactions. After studying this section will help you understand: spontaneous change, the first law of thermodynamics does not predict spontaneous change, freedom of particle motion,...

20p diepchilang 26-08-2021 17 1   Download

In this paper, continuing the research direction done in we consider further on phase structure of Reissner-Nordstr¨om charged black hole. The results show that there is a transition between small and large black holes (with horizonal radius change), the system share the same oscillatory behavior in pressure-volume graph, in temperature-entropy graph.

8p koxih_kothogmih5 04-09-2020 11 1   Download

A thorough analysis on critical exponents around the ferromagnetic-paramagnetic phase transition, using the ArrotteNoakes plots and KouveleFisher method, sheds light on the critical magnetic behavior and its association with the magnetocaloric effect in the Fe-La based alloys.

6p tamynhan4 06-09-2020 9 1   Download

Efficient and stable performance of the banking system underpins sustainable growth of any economy. Of late, several economic reforms have been initiated in India for facilitating growth and withstanding dynamics of global economy. In this context, the current study compares the performance of the selected private and public sector banks in India on a five year time horizon in order to discern any changes in the performance over a period of time.

16p chauchaungayxua2 04-01-2020 34 1   Download

This paper summarizes the symmetric image encryption results of 27 different algorithms, which include substitution-only, permutation-only or both phases. The cores of these algorithms are based on several discrete chaotic maps (Arnold’s cat map and a combination of three generalized maps), one continuous chaotic system (Lorenz) and two non-chaotic generators (fractals and chess-based algorithms).

16p kequaidan1 16-11-2019 13 0   Download

Magnetic and magnetotransport properties of two perovskite manganite samples of La0.7Ca0.3Mn0.9Zn0.1O3 and La0.7Ca0.3Mn0.95Cu0.05O3 prepared by conventional solid-state reaction have been studied in detail. Experimental results revealed that the temperature dependences of magnetization and resistance varied strongly around the phase-transition temperature. Maximum magnetoresistance (MR) values of La0.7Ca0.3Mn0.9Zn0.1O3 and La0.7Ca0.3Mn0.95Cu0.05O3 under an applied field of 400 Oe were about 21.4 % and 11.0 %, respectively. The maximum magnetic-entropy change (ΔSM) was 2.73 J/kg.K for La0.

10p nguathienthan 04-10-2019 19 0   Download

This system can be generated maximally entangled states. Specially, we can show that the entropy of entanglement and the maximally entangled states change dramatically when the initial conditions are different. The reasonableness obtained results is affirmed by the comparison to that of previous works.

6p vicolor2711 17-07-2019 9 1   Download

Chapter 7 (part 1) - Entropy: A measure of disorder. The objectives of Chapter 7 are to: Apply the second law of thermodynamics to processes; define a new property called entropy to quantify the second-law effects; establish the increase of entropy principle; Calculate the entropy changes that take place during processes for pure substances, incompressible substances, and ideal gases.

52p whocarea 05-09-2016 56 4   Download

The kinetics of the reversible thermal unfolding, irreversible thermal unfolding, and reductive unfolding processes of bovine pancreatic ribonuclease A (RNase A) were investi-gated in NaCl/Pi solutions. Image parameters including Shannon entropy, Hamming distance, mutual information and correlation coefficient were used in the analysis of the CD and 1D NMR spectra. The irreversible thermal unfolding transition of RNase A was not a cooperative process, pretransitional structure changes occur before the main thermal denaturation....

9p tumor12 22-04-2013 41 3   Download

This paper studies the impact of written language variations and the way it affects the capitalization task over time. A discriminative approach, based on maximum entropy models, is proposed to perform capitalization, taking the language changes into consideration. The proposed method makes it possible to use large corpora for training. The evaluation is performed over newspaper corpora using different testing periods. The achieved results reveal a strong relation between the capitalization performance and the elapsed time between the training and testing data periods. ...

4p hongphan_1 15-04-2013 41 1   Download

Study of the effect of Nd substitution for La on magnetocaloric effect (MCE) of polycrystalline perovskites (La1-xNdx)0.7Sr0.3MnO3 (x = 0.0, 0.2 , 0.4, 0.6, 0.8, 1.0 ) is presented. Large MCE is observed in all samples. The presence of Nd affects to both maximum magnetic entropy change, |∆Sm|max, and Curie temperature, TC. |∆Sm|max slightly reduces with low content and increases with high content of Nd and gets maximum value of 4.83 J/kg.K for x = 0.8. TC of the samples determined from the

6p tuanlocmuido 19-12-2012 39 2   Download